Digha Nikaya discourses are the longest in the Nikaya of the Pali Canon. Hence, probably it's less authentic (word by word of the Buddha) than other shorter suttas or Vinaya (rules). There are 2 discourses that I like: One is discribe the death (paranirvana) of the Buddha - compassion and encouragement from the Buddha; Another one is the Mahasatipatthana sutta - it discribe the "heart" of Buddhist meditation, the kind of meditation the the Buddha practiced himself. I believe this is the most important words of the Buddha (practice wise).
I disagree about some of the writing about the origin of human in one sutta near the end. I don't believe everything I read, or heard. I think the Buddha encourages us to dicipher for ourselves.
I think this translation is very readable yet not adding any flavors (ethics, believes...etc.). However, I have the feeling that the author could not convey all the deepest meanings in the Nikaya (maybe he's just a scholar). Beside that, this is the best translation to English of this Nikaya up to date (compare with the Pali Text Society version).
The problem is, with translations of the Nikayas and most of the Pali Canon is that translations are scarce, and therefore choosing between a reliable and non-reliable translation is sometimes difficult. Many scholars debate over correct Pali translations and there are some terms which have been unsetteled for a long time, ever since the inception of the Pali Text Society. Unfortuantly, this is one of the translations that contains a few errors here and there, as well as misleading footnotes. Learning Pali and Sanskrit is not an option for all of us, so sometimes, these will suffice.
Another interesting note is that the Nikayas are not really Theravada only (as is the Pali Canon), but these are some of the most fundamental texts of Buddhism dating back to the first Buddhist council, only a few years after the death of the Buddha.